rock-grinding

Updated: May 24, 2025

Several other important patents have been issued to Edison for crushing and grinding rolls, some of them being for elaborations and improvements of those above described but all covering methods of greater economy and effectiveness in rock-grinding. Edison's work on conveyors during the period of his ore-concentrating labors was distinctively original, ingenious and far in advance of the times.

Frank Lewis Dyer - Edison, His Life and Inventions